scholarly journals Nano-Honokiol Ameliorates the Cognitive Deficits in TgCRND8 Mice of Alzheimer’s Disease via Inhibiting Neuropathology and Modulating Gut Microbiota

Author(s):  
Chang Qu ◽  
Qiao-Ping Li ◽  
Zi-Ren Su ◽  
Siu-Po Ip ◽  
Qiu-Ju Yuan ◽  
...  
2020 ◽  
Author(s):  
Chang Qu ◽  
Qiao-Ping Li ◽  
Zi-Ren Su ◽  
Siu-Po Ip ◽  
Qiu-Ju Yuan ◽  
...  

Abstract Background Honokiol (HO) exerts neuroprotective effects in several animal models of Alzheimer’s disease (AD), but the poor dissolution hampers its bioavailability and therapeutic efficacy. A novel honokiol nanoscale drug delivery system (Nano-HO) with smaller size and excellent stability was developed in this study to improve the solubility and bioavailability of HO. Methods Male TgCRND8 mice were administered with Nano-HO or HO at the same dosage (20 mg/kg) by oral gavage daily for 17 consecutive weeks, followed by assessment of the spatial learning and memory functions with the Morris Water Maze test (MWMT). Results Nano-HO and HO could significantly improve cognitive deficits and inhibit neuroinflammation via suppressing the levels of tumor necrosis factor (TNF-α), interleukin 6 (IL-6) and IL-1β in the brain, preventing the activation of microglia (IBA-1) and astrocyte (GFAP), and reducing β-amyloid (Aβ) deposition in the cortex and hippocampus of TgCRND8 mice. In addition, Nano-HO and HO could modulate amyloid precursor protein (APP) processing and phosphorylation via suppressing β-secretase including β-site APP cleaving enzyme-1 (BACE-1) and phosphorylated APP (Thr 668), inhibiting γ-secretase including presenilin-1 (PS-1) and anterior pharynx-defective-1 (APH-1), as well as enhancing Aβ-degrading enzymes such as insulin degrading enzyme (IDE) and neprilysin (NEP). Moreover, Nano-HO remarkably inhibited tau hyperphosphorylation via decreasing the levels of p-tau (Thr 205) and p-tau (Ser 404), as well as regulating tau-related apoptosis proteins including caspase-3 and Bcl-2. Furthermore, Nano-HO and HO markedly attenuated the ratios of p-JNK/JNK and p-35/CDK5, while enhancing the ratio of p-GSK-3β (Ser9)/GSK-3β. On the other hand, Nano-HO and HO prevented the alterations on the composition of gut microbiota in TgCRND8 mice. Conclusions Nano-HO was more effective than regular HO in improving cognitive impairments in TgCRND8 mice via inhibiting Aβ deposition, tau hyperphosphorylation and neuroinflammation through suppressing the activation of JNK/CDK5/GSK-3β signaling pathway. Nano-HO was also more potently modulate the gut microbiota community to protect its stability as compared with that of regular HO. Our results amply indicated that HO with nano-sized drug delivery system has good potential for further development into therapeutic agent for AD treatment.


2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Yan-Fang Xian ◽  
Chang Qu ◽  
Yue Liu ◽  
Siu-Po Ip ◽  
Qiu-Ju Yuan ◽  
...  

Alzheimer’s disease (AD) is a common neurodegenerative disease characterized by progressive memory loss. Magnolol (MN), the main active ingredient of Magnolia officinalis, possesses anti-AD effects in several experimental models of AD. In this study, we aimed to explore whether MN could ameliorate the cognitive deficits in TgCRND8 transgenic mice and to elucidate its molecular mechanisms. Male TgCRND8 mice were orally administered with MN (20 and 40 mg/kg) daily for 4 consecutive months, followed by assessing the spatial learning and memory functions using the open-field, radial arm maze, and novel object recognition tests. The results demonstrated that MN (20 and 40 mg/kg) could markedly ameliorate the cognitive deficits in TgCRND8 mice. In addition, MN significantly increased the expression of postsynaptic density protein 93 (PSD93), PSD-95, synapsin-1, synaptotagmin-1, synaptophysin (SYN), and interleukin-10 (IL-10), while markedly reduced the protein levels of tumor necrosis factor alpha (TNF-α), IL-6, IL-1β, Aβ40, and Aβ42, and modulated the amyloid precursor protein (APP) processing and phosphorylation. Immunofluorescence showed that MN significantly suppressed the activation of microglia (Iba-1) and astrocytes (GFAP) in the hippocampus and cerebral cortex of TgCRND8 mice. Mechanistic studies revealed that MN could significantly increase the ratios of p-GSK-3β (Ser9)/GSK-3β, p-Akt (Ser473)/Akt, and p-NF-κB p65/NF-κB p65. These findings indicate that MN exerted cognitive deficits improving effects via suppressing neuroinflammation, amyloid pathology, and synaptic dysfunction through regulating the PI3K/Akt/GSK-3β and NF-κB pathways, suggesting that MN is a promising naturally occurring polyphenol worthy of further developing into a therapeutic agent for AD treatment.


Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 934
Author(s):  
Tiziana Bisogno ◽  
Anna Lauritano ◽  
Fabiana Piscitelli

Alzheimer’s disease (AD) is a neurodegenerative disease that progresses from mild cognitive impairment to severe dementia over time. The main clinical hallmarks of the disease (e.g., beta-amyloid plaques and neurofibrillary tangles) begin during preclinical AD when cognitive deficits are not yet apparent. Hence, a more profound understanding of AD pathogenesis is needed to develop new therapeutic strategies. In this context, the endocannabinoid (eCB) system and the gut microbiome are increasingly emerging as important players in maintaining the general homeostasis and the health status of the host. However, their interaction has come to light just recently with gut microbiota regulating the eCB tone at both receptor and enzyme levels in intestinal and adipose tissues. Importantly, eCB system and gut microbiome, have been suggested to play a role in AD in both animal and human studies. Therefore, the microbiome gut-brain axis and the eCB system are potential common denominators in the AD physiopathology. Hence, the aim of this review is to provide a general overview on the role of both the eCB system and the microbiome gut-brain axis in AD and to suggest possible mechanisms that underlie the potential interplay of these two systems.


2020 ◽  
Vol 17 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Dan Wang ◽  
Zhifu Fei ◽  
Song Luo ◽  
Hai Wang

Objectives: Alzheimer's disease (AD), also known as senile dementia, is a common neurodegenerative disease characterized by progressive cognitive impairment and personality changes. Numerous evidences have suggested that microRNAs (miRNAs) are involved in the pathogenesis and development of AD. However, the exact role of miR-335-5p in the progression of AD is still not clearly clarified. Methods: The protein and mRNA levels were measured by western blot and RNA extraction and quantitative real-time PCR (qRT-PCR), respectively. The relationship between miR-335-5p and c-jun-N-terminal kinase 3 (JNK3) was confirmed by dual-luciferase reporter assay. SH-SY5Y cells were transfected with APP mutant gene to establish the in vitro AD cell model. Flow cytometry and western blot were performed to evaluate cell apoptosis. The APP/PS1 transgenic mice were used as an in vivo AD model. Morris water maze test was performed to assess the effect of miR- 335-5p on the cognitive deficits in APP/PS1 transgenic mice. Results: The JNK3 mRNA expression and protein levels of JNK3 and β-Amyloid (Aβ) were significantly up-regulated, and the mRNA expression of miR-335-5p was down-regulated in the brain tissues of AD patients. The expression levels of miR-335-5p and JNK3 were significantly inversely correlated. Further, the dual Luciferase assay verified the relationship between miR-335- 5p and JNK3. Overexpression of miR-335-5p significantly decreased the protein levels of JNK3 and Aβ and inhibited apoptosis in SH-SY5Y/APPswe cells, whereas the inhibition of miR-335-5p obtained the opposite results. Moreover, the overexpression of miR-335-5p remarkably improved the cognitive abilities of APP/PS1 mice. Conclusion: The results revealed that the increased JNK3 expression, negatively regulated by miR-335-5p, may be a potential mechanism that contributes to Aβ accumulation and AD progression, indicating a novel approach for AD treatment.


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